Historical References

Design

Akagi obtains her crimson red color from her name, which means "red castle" or quite literally "crimson," among others.

Lines

Self-introduction - Akagi was originally intended to be an Amagi-class battlecruiser, but after Amagi, the original ship intended to be a carrier along with Kaga was damaged beyond feasible repair in the Great Kanto Earthquake, Akagi was selected for the role. The 1st Carrier Division is referring to the aircraft carrier unit both Akagi and Kaga were apart of, before they were both sunk at the Battle of Midway.

Return from mission - This is in reference to the "Five Minutes that Changed History," or the Battle of Midway, in which four carriers were sunk in a short time span, effectively changing the course of the entire war.

Additional Voice Lines (Enterprise) - It was dive bombers from the carrier Enterprise which would deal the fatal blow to Akagi at Midway.

Skills

Her skill "Preemptive Victory" refers to her participation in the Battle of Midway. Planes from Akagi participated in the raid on Midway, a preemptive victory that would later lead to her sinking.

Her skill "First Carrier Division" refers to her being in an aircraft carrier unit with Kaga.